Simply put, Desiccators are sealed containers having desiccants used for preserving moisture-sensitive substance like cobalt chloride paper for another use. A common use of desiccators is to protect chemicals which are hygroscopic or which react with water from humidity.
Desiccators are usually made of heavy glass like borosilicate glass (pyrex). The apparatus usually incorporates a removable platform on which items meant for keeping in the desiccator are placed. The desiccant, such as silica gel, fills the space under the platform thereby protecting the substance from atmospheric moisture.
Porcelain desiccators are the most common type of desiccator used in laboratories. These are made of hard ceramic material that provides good strength and endurance features. Porcelain desiccator is very safe to use in a laboratory environment.